%epistome%

{ ‖ } n. [ NL. epistoma, fr. Gr. 'epi` upon + &unr_;, &unr_;, mouth. ] (Zoöl.) (a) The region between the antennæ and the mouth, in Crustacea. (b) A liplike organ that covers the mouth, in most Bryozoa. See Illust., under Entoprocta. [ 1913 Webster ]